Interference often hinders performance of communication systems. One type of interference often encountered by a user within a communication system is interference generated by the transmissions of other users. This is typically caused by many users transmitting within the same channel (e.g., frequency band, time slot, or spreading code), and referred to as co-channel interference. In order to reduce co-channel interference many communication systems employ a channel reuse pattern, where adjacent transmitters transmit on different channels. However, given the price of spectrum, future communications systems will be characterized by aggressive reuse patterns that will result in significantly increased levels of co-channel interference.
Various methods have been proposed for dealing with severe co-channel interference in communication systems, and especially in cellular communication systems. Signal spreading methods (such as direct sequence spread spectrum) can be used to provide processing gain over co-channel interference, but this limits the data rate that can be supported. Moreover, dynamic channel allocation methods have been proposed, but these methods are difficult to implement because they require monitoring of the channel quality, the channel availability, and they also require communication links to be established between different base stations so that the channel allocation process can be controlled and monitored. Moreover, as cellular systems evolve from circuit-centric operation to packet-centric operation, the channel utilization pattern in any given cell becomes much more dynamic, leading to further implementation difficulties (e.g., the channel utilization may change more quickly than the response time of the channel allocation process, making it essentially ineffective). Therefore, there is a need for a method and apparatus that can reduce co-channel interference in a dynamic interference environment, and that can be realized without establishing communications between base stations in different cells.